Corrosion and wear behaviors of boronized AISI 316L stainless steel

In this study, the effects of a boronizing treatment on the corrosion and wear behaviors of AISI 316L austenitic stainless steel (AISI 316L) were examined. The corrosion behavior of the boronized samples was studied via electrochemical methods in a simulation body fluid (SBF) and the wear behavior was examined using the ball-on-disk wear method. It was observed that the boride layer that formed on the AISI 316L surface had a flat and smooth morphology. Furthermore, X-ray diffraction analyses show that the boride layer contained FeB, Fe₂B, CrB, Cr₂B, NiB, and Ni₂B phases. Boride layer thickness increased with an increasing boronizing temperature and time. The boronizing treatment also increased the surface hardness of the AISI 316L. Although there was no positive effect of the coating on the corrosion resistance in the SBF medium. Furthermore, a decrease in the friction coefficient was recorded for the boronized AISI 316L. As the boronizing temperature increased, the wear rate decreased in both dry and wet mediums. As a result, the boronizing treatment contributed positively to the wear resistance by increasing the surface hardness and by decreasing the friction coefficient of the AISI 316L.     

Field correlation for flat-topped beam in non-Kolmogorov turbulent medium

Absolute field correlation of flat-topped beam in non-Kolmogorov turbulent medium is examined at the receiver plane. The power law exponent increase affects absolute field correlation inversely. It is found that the absolute field correlation decreases when the propagation distance, deviation from the receiver axis, diagonal transverse distance from the receiver point and turbulence strength increase. Beam flatness order increase yields smaller absolute field correlation. For the employed parameters, the flat-topped beam attains higher absolute field correlation when the wavelength and the source size increase.     

A serial CT scan and MRI verification of diffuse cerebrospinal gliomatosis: a case report with stereotactic diagnosis and radiological confirmation

The purpose of this work was to study H2/CO2-utilizing acetogenic population in the colons of non-methane-producing individuals harboring low numbers of methanogenic archaea. Among the 50 H2-consuming acetogenic strains isolated from four fecal samples and an in vitro semi-continuous culture enrichment, with H2/CO2 as sole energy source, 20 were chosen for further studies. All isolates were Gram-positive strict anaerobes. Different morphological types were identified, providing evidence of generic diversity. All acetogenic strains characterized used H2/CO2 to form acetate as the sole metabolite, following the stoichiometric equation of reductive acetogenesis. These bacteria were also able to use a variety of organic compounds for growth. The major end product of glucose fermentation was acetate, except for strains of cocci that mainly produced lactate. Yeast extract was not necessary, but was stimulatory for growth and acetogenesis from H2/CO2.     

Concomitant rotator cuff tear and brachial plexus injury in association with anterior shoulder dislocation: unhappy triad of the shoulder

High incidences of nerve lesions or rotator cuff tears in association with shoulder dislocations have been reported. However, the simultaneous occurrence of these three lesions has only been reported once previously. This case is an example of a not so uncommon injury, which emphasizes the importance of looking for associated brachial plexus and rotator cuff lesions when examining a patient with shoulder dislocation.     

An artificial intelligence-based spectrum sensing methodology for LoRa and cognitive radio networks

The artificial intelligence-based spectrum sensing approach is extremely important in terms of effective bandwidth utilization for low power wide area networks (LPWANs) based on cognitive radio networks (CRNs). Most studies perform spectrum detection with CRNs using optimization or deep neural network methods. However, optimization-based spectrum detection approaches based on current LPWANs are scarce. For this purpose, in this study, a hybrid optimization methodology integrated with CRNs is proposed for LoRa, which is one of the most compatible LPWAN technologies in the Internet of Things (IoTs) recently. In the particle swarm optimization (PSO) part of this hybrid methodology, agent users are created so that secondary users (SUs) could use the licensed band of primary users (PUs) in cognitive radio. On the genetic algorithm side, LoRa error rates are minimized in order to further improve the performance of the proposed method. In this way, effective spectrum sensing is performed in the LoRa network. Various LoRa-CRN experiments have been carried out in the simulation environment, and the probability of detection and false alarm performances have been compared with both theoretical and proposed approaches in terms of quality estimation parameters. It is clear from the results that the proposed methods give successful results for the LoRa-CRNs.     

Removal of copper,nickel, cobalt and manganese from aqueous solution by kaolinite

The removal of some heavy metals such as Mn(II), Co(II), Ni(II), and Cu(II) from aqueous solution is studied using a raw kaolinite. The sorption of these metals on kaolinite conformed to linear form of Langmuir adsorption equation. Langmuir C(m) constants for each metal were found as 0.446 mg/g (Mn), 0.919 mg/g (Co), 1.669 mg/g (Ni), 10787 mg/g (Cu) at 25 degrees C, respectively. Also, kinetic and thermodynamic parameters such as enthalpy (deltaH), free energy (deltaG) and entropy (deltaS) were calculated and these values show that adsorption of heavy metal on kaolinite was an endothermic process and the process of adsorption was favoured at high temperatures.     

Resource recovery as a sustainable perspective for the remediation of mining wastes: rehabilitation of the CMC mining waste site in Northern Cyprus

Bulletin of Engineering Geology and the Environment - This paper highlights resource recovery and stabilization as the novel approach adopted in the rehabilitation strategy of the abandoned copper...     

Influence of vitamin (B1, B6, B9, B12, C) and ions (Cu2+, Mn2+, PO4 3−) on kefir grain biomass growth

The aim of the present study was to investigate the effects of additions of various vitamins (B₁, B₆, B₉, B₁₂, and C) and minerals (CuSO₄·H₂O, MnSO₄·H₂O, and Na₃PO₄·12 H₂O) on the propagation of kefir grains. The activated kefir grains were inoculated into very low fat (0.1%) cows’ milk under constant temperature (25°C) and impeller speed (100 rpm) for a propagation time of 24 h. After evaluation of the experimental data, the most influential mineral addition providing 39% increase of kefir grain biomass was found to be Na₃PO₄·12 H₂O with a concentration of 0.30 g phosphate (PO₄ ^3?) ion/L. At this optimal condition, a model was also derived for the kefir grain biomass concentration representing pH dependence. This study demonstrated the basis for further research in the direction of kefir grain biomass growth considering the effect of additions of vitamins and minerals to other researchers working in the same field and to dairy industry as well.     

Development of an Amperometric Hydrogen Peroxide Biosensor based on the Immobilization of Horseradish Peroxidase onto Nickel Ferrite Nanoparticle-Chitosan Composite

Nano-Micro Letters - Nickel ferrite (NiFe2O4) nanoparticles have been dispersed in chitosan solution in order to fabricate nanocomposite films. Horseradish peroxidase (HRP) has been immobilized...     

Neutronic analysis of a high power density hybrid reactor using innovative coolants

In this study, neutronic investigation of a deuterium-tritium (DT) driven hybrid reactor using ceramic uranium fuels, namely UC, UO₂ or UN under a high neutron wall load (NWL) of 10MW/m² at the first wall is conducted over a period of 24 months for fissile fuel breeding for light water reactors (LWRs). New substances, namely, Flinabe or Li₂₀Sn₈₀ are used as coolants in the fuel zone to facilitate heat transfer out of the blanket. Natural lithium is also utilized for comparison to these two innovative coolants. Neutron transport calculations are performed on a simple experimental hybrid blanket with cylindrical geometry with the help of the SCALE 4.3 System by solving the Boltzmann transport equation with the XSDRNPM code in 238 neutron groups and an S₈-P₃ approximation. The investigated blanket using Flinabe or Li₂₀Sn₈₀ shows better fissile fuel breeding and fuel enrichment characteristics compared to that with natural lithium which shows that these two innovative coolants can be used in hybrid reactors for higher fissile fuel breeding performance. Furthermore, using a high NWL of 10MW/m² at the first wall of the investigated blanket can decrease the time for fuel rods to reach the level for charging in LWRs.